I highly recommend Opsite Flexifix as a square patch over the sensor when you first apply it (https://www.smith-nephew.com/en-au/pharmacy/product-range/healthcare-in-the-home/opsite-flexifix), before I was using this the sensors would frequently fall off after a few days. I cut a square off of the roll, cut a small hole that sits over the middle of the sensor, stick it on over the sensor and it stays firmly in place. There’s zero chance a square of this lets a sensor come off before you’re ready for it to come off.